Cyalume ChemLight Military Grade LightShape Circle Marker, Blue, 4 Hour Duration (Pack of 10) FOUR HOURS OF ILLUMINATION PER LIGHT MARKER can be seen from up to a mile away for bright, reliable marking DURABLE, ADHESIVE BACKING creates a safe and secure bond to any surface for emergency procedures, triage tagging and trail marking MADE IN THE USA UNDER STRICT QUALITY GUIDELINES to guarantee consistent and excellent results in every product MAINTENANCE-FREE PERFORMANCE guarantees a four-year shelf life and theres no need to check or change batteries 100% NONTOXIC, WATERPROOF AND NONFLAMMABLE CONSTRUCTION means LightShape will perform safely no matter the environment